<s>
Deno	B-Application
is	O
a	O
runtime	B-Device
for	O
JavaScript	B-Language
,	O
TypeScript	B-Language
,	O
and	O
WebAssembly	B-Language
that	O
is	O
based	O
on	O
the	O
V8	B-Language
JavaScript	I-Language
engine	I-Language
and	O
the	O
Rust	B-Application
programming	I-Application
language	I-Application
.	O
</s>
<s>
Deno	B-Application
was	O
co-created	O
by	O
Ryan	O
Dahl	O
,	O
who	O
also	O
created	O
Node.js	B-Language
.	O
</s>
<s>
Deno	B-Application
explicitly	O
takes	O
on	O
the	O
role	O
of	O
both	O
runtime	B-Device
and	O
package	B-Application
manager	I-Application
within	O
a	O
single	O
executable	B-Application
,	O
rather	O
than	O
requiring	O
a	O
separate	O
package-management	B-Application
program	I-Application
.	O
</s>
<s>
Deno	B-Application
was	O
announced	O
on	O
by	O
Ryan	O
Dahl	O
in	O
his	O
talk	O
"	O
10	O
Things	O
I	O
Regret	O
About	O
Node.js	B-Language
"	O
.	O
</s>
<s>
In	O
his	O
talk	O
,	O
Dahl	O
mentioned	O
his	O
regrets	O
about	O
the	O
initial	O
design	O
decisions	O
with	O
Node.js	B-Language
,	O
focusing	O
on	O
his	O
choices	O
of	O
not	O
using	O
promises	B-Operating_System
in	O
API	B-General_Concept
design	O
,	O
usage	O
of	O
the	O
legacy	O
build	O
system	O
GYP	B-Operating_System
,	O
node_modules	O
and	O
package.json	O
,	O
leaving	O
out	O
file	B-Application
extensions	O
,	O
magical	O
module	O
resolution	O
with	O
index.js	O
and	O
breaking	O
the	O
sandboxed	O
environment	O
of	O
V8	B-Language
.	O
</s>
<s>
He	O
eventually	O
presented	O
the	O
prototype	O
of	O
Deno	B-Application
,	O
aiming	O
to	O
achieve	O
system	O
call	O
bindings	O
through	O
message	O
passing	O
with	O
serialization	O
tools	O
such	O
as	O
Protocol	B-Protocol
Buffers	I-Protocol
,	O
and	O
to	O
provide	O
command	B-Application
line	I-Application
flags	O
for	O
access	O
control	O
.	O
</s>
<s>
Deno	B-Application
was	O
initially	O
written	O
in	O
Go	B-Application
and	O
used	O
Protocol	B-Protocol
Buffers	I-Protocol
for	O
serialization	O
between	O
privileged	O
(	O
Go	B-Application
,	O
with	O
system	O
call	O
access	O
)	O
and	O
unprivileged	O
(	O
V8	B-Language
)	O
sides	O
.	O
</s>
<s>
However	O
,	O
Go	B-Application
was	O
soon	O
replaced	O
with	O
Rust	B-Application
due	O
to	O
concerns	O
of	O
double	O
runtime	B-Device
and	O
garbage	B-General_Concept
collection	I-General_Concept
pressure	O
.	O
</s>
<s>
Tokio	B-Application
was	O
introduced	O
in	O
place	O
of	O
libuv	B-Language
as	O
the	O
asynchronous	O
event-driven	O
platform	O
,	O
and	O
FlatBuffers	B-Protocol
was	O
adopted	O
for	O
faster	O
,	O
"	O
zero-copy	O
"	O
serialization	O
and	O
deserialization	O
but	O
later	O
in	O
August	O
2019	O
,	O
FlatBuffers	B-Protocol
was	O
removed	O
after	O
publishing	O
benchmarks	O
that	O
measured	O
a	O
significant	O
overhead	O
of	O
serialization	O
in	O
April	O
2019	O
.	O
</s>
<s>
A	O
standard	O
library	O
,	O
modeled	O
after	O
Go	B-Application
's	O
standard	O
library	O
,	O
was	O
created	O
in	O
November	O
2018	O
to	O
provide	O
extensive	O
tools	O
and	O
utilities	O
,	O
partially	O
solving	O
Node.js	B-Language
'	O
dependency	O
tree	O
explosion	O
problem	O
.	O
</s>
<s>
The	O
official	O
Deno	B-Application
1.0	O
was	O
released	O
on	O
May	O
13	O
,	O
2020	O
.	O
</s>
<s>
Deno	B-Application
Deploy	O
,	O
inspired	O
by	O
Cloudflare	B-Application
Workers	O
,	O
was	O
released	O
on	O
June	O
23	O
,	O
2021	O
.	O
</s>
<s>
General	O
availability	O
of	O
Deno	B-Application
Deploy	O
is	O
eyed	O
for	O
the	O
third	O
quarter	O
of	O
2022	O
.	O
</s>
<s>
Deno	B-Application
Fresh	O
1.0	O
was	O
announced	O
June	O
28	O
,	O
2022	O
.	O
</s>
<s>
It	O
features	O
a	O
new	O
full	O
stack	O
web	O
framework	O
for	O
Deno	B-Application
that	O
sends	O
zero	O
JavaScript	B-Language
to	O
the	O
client	O
.	O
</s>
<s>
Deno	B-Application
SaaSKit	O
beta	O
was	O
announced	O
April	O
4	O
,	O
2023	O
.	O
</s>
<s>
It	O
is	O
an	O
open-source	B-Application
,	O
modern	O
SaaS	O
template	O
built	O
with	O
Fresh	O
and	O
Deno	B-Application
.	O
</s>
<s>
Deno	B-Application
aims	O
to	O
be	O
a	O
productive	O
and	O
secure	O
scripting	B-Language
environment	O
for	O
the	O
modern	O
programmer	O
.	O
</s>
<s>
Similar	O
to	O
Node.js	B-Language
,	O
Deno	B-Application
emphasizes	O
event-driven	B-Application
architecture	I-Application
,	O
providing	O
a	O
set	O
of	O
non-blocking	B-Architecture
core	O
I/O	O
utilities	O
,	O
along	O
with	O
their	O
blocking	O
versions	O
.	O
</s>
<s>
Deno	B-Application
could	O
be	O
used	O
to	O
create	O
web	B-Application
servers	I-Application
,	O
perform	O
scientific	O
computations	O
,	O
etc	O
.	O
</s>
<s>
Deno	B-Application
is	O
open	B-Application
source	I-Application
software	I-Application
under	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
Deno	B-Application
and	O
Node.js	B-Language
are	O
both	O
runtimes	O
built	O
on	O
Google	O
's	O
V8	B-Language
JavaScript	I-Language
engine	I-Language
,	O
the	O
same	O
engine	O
used	O
in	O
Google	B-Application
Chrome	I-Application
.	O
</s>
<s>
They	O
both	O
have	O
internal	O
event	B-General_Concept
loops	I-General_Concept
and	O
provide	O
command-line	B-Application
interfaces	I-Application
for	O
running	O
scripts	O
and	O
a	O
wide	O
range	O
of	O
system	O
utilities	O
.	O
</s>
<s>
Deno	B-Application
mainly	O
deviates	O
from	O
Node.js	B-Language
in	O
the	O
following	O
aspects	O
:	O
</s>
<s>
Supports	O
only	O
ES	O
Modules	O
like	O
browsers	B-Application
where	O
Node.js	B-Language
supports	O
both	O
ES	O
Modules	O
and	O
CommonJS	B-Language
.	O
</s>
<s>
CommonJS	B-Language
support	O
in	O
Deno	B-Application
is	O
possible	O
by	O
using	O
a	O
compatibility	O
layer	O
.	O
</s>
<s>
Supports	O
only	O
URLs	O
for	O
loading	O
local	O
or	O
remote	O
dependencies	O
,	O
similar	O
to	O
browsers	B-Application
.	O
</s>
<s>
Node.js	B-Language
supports	O
both	O
URLs	O
and	O
modules	O
.	O
</s>
<s>
Does	O
not	O
require	O
a	O
package	B-Application
manager	I-Application
for	O
resource	O
fetching	O
,	O
thus	O
no	O
need	O
for	O
a	O
registry	O
like	O
npm	B-Language
.	O
</s>
<s>
Supports	O
TypeScript	B-Language
out	O
of	O
the	O
box	O
,	O
using	O
a	O
snapshotted	O
TypeScript	B-Language
compiler	B-Language
or	O
the	O
swc	O
compiler	B-Language
with	O
caching	O
mechanisms	O
.	O
</s>
<s>
Aims	O
for	O
better	O
compatibility	O
with	O
browsers	B-Application
with	O
a	O
wide	O
range	O
of	O
Web	B-General_Concept
APIs	I-General_Concept
.	O
</s>
<s>
Restricts	O
file	B-Application
system	I-Application
and	O
network	O
access	O
by	O
default	O
in	O
order	O
to	O
run	O
sandboxed	O
code	O
.	O
</s>
<s>
Supports	O
a	O
single	O
API	B-General_Concept
to	O
utilize	O
promises	B-Operating_System
,	O
ES6	B-Language
and	O
TypeScript	B-Language
features	O
whereas	O
Node.js	B-Language
supports	O
both	O
promise	O
and	O
callback	O
APIs	B-General_Concept
.	O
</s>
<s>
Minimizes	O
core	O
API	B-General_Concept
size	O
,	O
while	O
providing	O
a	O
large	O
standard	O
library	O
with	O
no	O
external	O
dependencies	O
.	O
</s>
<s>
Uses	O
message	O
passing	O
channels	O
for	O
invoking	O
privileged	O
system	O
APIs	B-General_Concept
and	O
using	O
bindings	O
.	O
</s>
<s>
On	O
March	O
29	O
,	O
2021	O
,	O
Deno	B-Application
Land	O
Inc	O
was	O
announced	O
,	O
with	O
backing	O
in	O
millions	O
of	O
dollars	O
from	O
Shasta	O
Ventures	O
,	O
Mozilla	O
Corporation	O
and	O
a	O
few	O
others	O
.	O
</s>
<s>
It	O
was	O
established	O
to	O
further	O
the	O
development	O
of	O
Deno	B-Application
and	O
provide	O
a	O
commercial	O
offering	O
to	O
users	O
.	O
</s>
<s>
A	O
year	O
on	O
,	O
Deno	B-Application
announced	O
a	O
further	O
$21	O
million	O
in	O
Series	O
A	O
funding	O
led	O
by	O
Sequoia	O
Capital	O
.	O
</s>
<s>
VersionLatest	O
patch	O
releaseRelease	O
dateDate	O
of	O
last	O
patch	O
releaseDescription	O
2018-08-23	O
2018-11-12	O
Rust	B-Application
rewrite	O
and	O
V8	B-Language
snapshot	O
2018-11-27	O
2019-02-08	O
Mildly	O
usable	O
2019-02-18	O
2019-04-25	O
Instead	O
of	O
importing	O
a	O
"	O
deno	B-Application
"	O
module	O
,	O
there	O
is	O
now	O
a	O
global	O
variable	O
called	O
"	O
Deno	B-Application
"	O
2020-05-13	O
2020-06-03	O
Initial	O
production	O
release	O
with	O
CLI	O
,	O
first-class	O
TypeScript	B-Language
Support	O
,	O
Rust	B-Application
APIs	B-General_Concept
and	O
improvements	O
in	O
HTTP	B-Application
server	I-Application
performance	O
2020-06-12	O
2020-07-03	O
Various	O
additions	O
and	O
fixes	O
to	O
the	O
CLI	O
,	O
Rust	B-Application
1.44.0	O
2020-07-13	O
2020-08-08	O
Various	O
additions	O
and	O
fixes	O
to	O
the	O
CLI	O
2020-08-13	O
2020-09-04	O
Various	O
additions	O
and	O
fixes	O
to	O
the	O
CLI	O
,	O
various	O
improvements	O
to	O
the	O
Deno	B-Application
language	O
,	O
TypeScript	B-Language
3.9.7	O
2020-09-13	O
2020-10-10	O
New	O
web	O
standard	O
WebSocket	O
API	B-General_Concept
,	O
automatic	O
restarts	O
on	O
file	B-Application
change	O
,	O
integrated	O
test	O
coverage	O
2020-10-27	O
2020-11-23	O
Faster	O
tree-shaking	O
and	O
bundling	O
,	O
refactored	O
REPL	O
2020-12-08	O
2020-12-30	O
Compile	B-Language
standalone	O
binaries	O
via	O
"	O
deno	B-Application
compile	B-Language
"	O
,	O
support	O
TypeScript	B-Language
4.1	O
,	O
experimental	O
support	O
for	O
Mac	O
ARM64	O
2021-02-052021-02-19	O
Cross	O
compilation	B-Language
and	O
60%	O
smaller	O
binaries	O
for	O
deno	B-Application
compile	B-Language
,	O
a	O
DNS	O
resolver	B-Operating_System
API	B-General_Concept
,	O
support	O
for	O
data	O
URLs	O
in	O
import	O
statements	O
and	O
web	O
workers	O
2021-03-022021-04-02	O
Experimental	O
support	O
for	O
WebGPU	O
API	B-General_Concept
,	O
built-in	O
internationalization	O
APIs	B-General_Concept
enabled	O
,	O
support	O
for	O
fetching	O
private	O
modules	O
,	O
revamped	O
coverage	O
tooling	O
,	O
support	O
for	O
TypeScript	B-Language
4.2	O
2021-04-132021-04-23	O
Native	O
HTTP/2	O
web	B-Application
server	I-Application
,	O
Faster	O
calls	O
into	O
Rust	B-Application
with	O
serde_v8	O
,	O
Blob	O
URL	O
support	O
&	O
improvements	O
to	O
fetch	O
api	B-General_Concept
,	O
Import	O
completions	O
in	O
the	O
LSP	O
,	O
Interactive	O
permission	O
prompt	O
2021-05-112021-05-17	O
Improvements	O
to	O
the	O
built	O
in	O
test	O
runner	O
,	O
structured	O
clone	O
support	O
in	O
Web	O
Workers	O
,	O
Web	O
Storage	O
API	B-General_Concept
,	O
support	O
for	O
remote	O
import	O
maps	O
2021-06-082021-06-29	O
Official	O
docker	O
images	O
,	O
more	O
web	O
crypto	O
APIs	B-General_Concept
added	O
,	O
BroadcastChannel	O
,	O
abortable	O
fetch	O
,	O
deno	B-Application
lint	O
stabilized	O
2021-07-132021-07-26	O
Support	O
for	O
generateKey	O
,	O
sign	O
and	O
verify	O
web	O
crypto	O
APIs	B-General_Concept
,	O
native	O
WebSocket	O
server	O
support	O
,	O
TypeScript	B-Language
support	O
in	O
REPL	O
,	O
support	O
for	O
MessagePort	O
and	O
MessageChannel	O
2021-08-102021-08-23	O
Native	O
HTTP	B-Application
web	I-Application
server	I-Application
stabilization	O
,	O
support	O
for	O
self.structuredClone( )	O
,	O
AbortSignal	O
support	O
,	O
support	O
for	O
navigator.hardwareConcurrency	O
API	B-General_Concept
,	O
experimental	O
WebSocketStream	O
API	B-General_Concept
,	O
FFI	O
replaces	O
native	O
plugin	O
system	O
2021-09-142021-10-04	O
URLPattern	O
,	O
file	B-Application
locking	O
APIs	B-General_Concept
,	O
mutual	O
TLS	O
support	O
in	O
fetch	O
,	O
TypeScript	B-Language
4.4	O
,	O
URL	O
parsing	O
and	O
std/http	O
performance	O
improvements	O
2021-10-122021-10-25	O
New	O
crypto	O
APIs	B-General_Concept
,	O
deno	B-Application
uninstall	O
subcommand	O
,	O
nested	O
testing	O
API	B-General_Concept
,	O
FFI	O
improvements	O
,	O
new	O
—	O
compat	O
flag	O
for	O
improved	O
Node	O
compatibility	O
2021-11-092021-12-03	O
Fetch	O
support	O
for	O
file	B-Application
URLs	O
,	O
new	O
unstable	O
signal	O
listener	O
API	B-General_Concept
,	O
support	O
for	O
specifying	O
a	O
reason	O
when	O
aborting	O
an	O
AbortSignal	O
,	O
improvements	O
to	O
Web	O
Streams	O
API	B-General_Concept
,	O
findLast	O
and	O
findLastIndex	O
array	O
methods	O
,	O
Deno	B-Application
to	O
npm	B-Language
package	O
build	O
tool	O
2021-12-162022-01-12	O
Import	O
assertions	O
and	O
JSON	O
modules	O
,	O
improvements	O
to	O
the	O
Web	O
Cryptography	O
API	B-General_Concept
,	O
unref	O
timers	O
,	O
unstable	O
support	O
for	O
negotiating	O
ALPN	O
,	O
TypeScript	B-Language
4.5	O
2022-01-202022-01-20	O
Config	O
file	B-Application
auto-discovery	O
,	O
completion	O
of	O
Web	O
Cryptography	O
API	B-General_Concept
,	O
stabilization	O
of	O
test	O
steps	O
API	B-General_Concept
,	O
FFI	O
improvements	O
,	O
LSP	O
improvements	O
2022-02-172022-03-10New	O
Deno	B-Application
vendor	O
dependency	O
,	O
default	O
permission	O
prompt	O
,	O
new	O
web	O
streams	O
for	O
files	O
,	O
network	O
sockets	O
and	O
stdio	O
,	O
CompressionStream	O
and	O
DecompressionStream	O
supported	O
,	O
better	O
errors	O
for	O
ops	O
and	O
resource	O
sanistizers	O
,	O
improved	O
console	O
log	O
2022-04-142022-03-16Faster	O
calls	O
into	O
Rust	B-Application
,	O
auto-compression	O
for	O
HTTP	O
response	O
bodies	O
,	O
new	O
subcommands	O
(	O
deno	B-Application
bench	O
,	O
deno	B-Application
task	O
)	O
,	O
security	O
improvements	O
,	O
stricter	O
defaults	O
in	O
programmatic	O
permission	O
,	O
TypeScript	B-Language
4.6	O
,	O
V8	B-Language
10.0	O
2022-04-202022-05-12Various	O
improvements	O
to	O
the	O
Deno	B-Application
language	O
,	O
VSCode	O
extension	O
,	O
and	O
REPL	O
.	O
</s>
<s>
Run	O
a	O
Deno	B-Application
script	O
without	O
any	O
file	B-Application
system	I-Application
or	O
network	O
permissions	O
(	O
sandbox	O
mode	O
)	O
:Explicit	O
flags	O
are	O
required	O
to	O
enable	O
permissions:To	O
inspect	O
the	O
dependency	O
tree	O
of	O
the	O
script	O
,	O
use	O
the	O
info	O
subcommand:A	O
basic	O
Hello	O
,	O
World	O
!	O
</s>
<s>
program	O
in	O
Deno	B-Application
(	O
similar	O
to	O
Node.js	B-Language
)	O
:Global	O
Deno	B-Application
namespaces	O
expose	O
APIs	B-General_Concept
that	O
are	O
not	O
available	O
in	O
the	O
browser	B-Application
.	O
</s>
<s>
Unix	B-Application
cat	B-Device
program	I-Device
could	O
be	O
implemented	O
as	O
follows:Note:Deno.copy	O
function	O
used	O
above	O
is	O
similar	O
to	O
Go	B-Application
's	O
io.Copy	O
,	O
where	O
stdout	O
(	O
standard	B-Operating_System
output	I-Operating_System
)	O
is	O
the	O
destination	O
Writer	O
,	O
and	O
file	B-Application
is	O
the	O
source	O
Reader	O
.	O
</s>
<s>
To	O
run	O
this	O
program	O
,	O
we	O
need	O
to	O
enable	O
read	O
permission	O
to	O
the	O
filesystem:Deno	O
script	O
for	O
a	O
basic	O
HTTP	O
server:Deno	O
automatically	O
downloads	O
and	O
caches	O
the	O
remote	O
standard	O
library	O
files	O
when	O
the	O
script	O
is	O
run	O
,	O
and	O
then	O
compile	B-Language
the	O
code	O
.	O
</s>
<s>
Similarly	O
,	O
we	O
can	O
run	O
a	O
standard	O
library	O
script	O
(	O
such	O
as	O
a	O
file	B-Application
server	I-Application
)	O
directly	O
without	O
explicitly	O
downloading	O
,	O
by	O
providing	O
the	O
URL	O
as	O
the	O
input	O
filename	O
(	O
-A	O
turns	O
on	O
all	O
permissions	O
)	O
:	O
</s>
